[CC ing build, libquadmath, libcilkrts maintainers]
On 01/23/2015 02:53 AM, Ian Lance Taylor wrote:
> On Thu, Jan 22, 2015 at 3:44 PM, Matthias Klose <d...@ubuntu.com> wrote:
>>
>> However for the libbacktrace and the libsanitizer builds, the
>> AM_ENABLE_MULTILIB
>> macro is included way too late. Scan the generated configure file for
>> "cross_compiling" and see that the above snippet is added after the failing
>> checks. The fix seems to be simple, just move the AM_ENABLE_MULTILIB macro
>> up so
>> that the "cross_compiling" value is corrected before it is tested. This is
>> what
>> the patch is doing.
>>
>> However ... for every runtime library there is still something wrong, at
>> least
>> one linker check in the generated configure is done before the expansion of
>> the
>> AM_ENABLE_MULTILIB macro. I'm not trying to fix that with this patch ...
>> autoconf offers a AC_REQUIRE macro, so AM_ENABLE_MULTILIB should add one to
>> ensure that this macros is always expanded before the first check for
>> "cross_compiling", but I'm not sure which one.
>>
>> Small patch, but took me some time to find out :-/
>>
>> This patch should go to trunk and all active branches. Ok to check in?
>
> The libbacktrace library is unusual because we build it for both the
> host and the target. When building for the host, we do not want to
> multilib it--that would make no sense. You've moved the
> AM_ENABLE_MULTILIB out of the test -n "${with_target_subdir}"; don't
> do that.
ok, moved the macro into the test again.
> It's fine with me if you move AM_ENABLE_MULTILIB earlier as long as
> you keep the test.
>
> Probably a build maintainer should take a look at this patch.
CCed, and there are more directories needing an update: libquadmath and
libcilkrts. Note that libcilkrts didn't have an AM_ENABLE_MULTILIB call at all,
but nevertheless builds the multilib libraries.
I then tried to patch config.multi.m4 to warn when _AC_COMPILER_EXEEXT was
called before, but I didn't see any warning emitted. No idea yet how this is
supposed to work.
--- a/src/config/multi.m4
+++ b/src/config/multi.m4
@@ -12,6 +12,9 @@
# ---------------------------------------------------
# Add --enable-multilib to configure.
AC_DEFUN([AM_ENABLE_MULTILIB],
+# warn if _AC_COMPILER_EXEEXT was called before (using cross_compiling)
+AC_BEFORE([$0], [_AC_COMPILER_EXEEXT])
+
[# Default to --enable-multilib
AC_ARG_ENABLE(multilib,
[ --enable-multilib build many library versions (default)],
The attached patch just moves the AM_ENABLE_MULTILIB calls up in the files, so
that these are found before GCC_NO_EXECUTABLES (which is not called in every
libXXdir) and AC_PROC_CC.
x32 multilib enabled x86_64-linux-gnu and i686-linux-gnu configurations built
successfully on a non-x32 enabled kernel.
Matthias
Index: b/src/libbacktrace/configure.ac
===================================================================
--- a/src/libbacktrace/configure.ac
+++ b/src/libbacktrace/configure.ac
@@ -34,6 +34,10 @@ AC_INIT(package-unused, version-unused,,
AC_CONFIG_SRCDIR(backtrace.h)
AC_CONFIG_HEADER(config.h)
+if test -n "${with_target_subdir}"; then
+ AM_ENABLE_MULTILIB(, ..)
+fi
+
AC_CANONICAL_SYSTEM
target_alias=${target_alias-$host_alias}
@@ -83,7 +87,6 @@ backtrace_supported=yes
if test -n "${with_target_subdir}"; then
# We are compiling a GCC library. We can assume that the unwind
# library exists.
- AM_ENABLE_MULTILIB(, ..)
BACKTRACE_FILE="backtrace.lo simple.lo"
else
AC_CHECK_HEADER([unwind.h],
Index: b/src/libsanitizer/configure.ac
===================================================================
--- a/src/libsanitizer/configure.ac
+++ b/src/libsanitizer/configure.ac
@@ -5,6 +5,8 @@ AC_PREREQ([2.64])
AC_INIT(package-unused, version-unused, libsanitizer)
AC_CONFIG_SRCDIR([include/sanitizer/common_interface_defs.h])
+AM_ENABLE_MULTILIB(, ..)
+
AC_MSG_CHECKING([for --enable-version-specific-runtime-libs])
AC_ARG_ENABLE(version-specific-runtime-libs,
[ --enable-version-specific-runtime-libs Specify that runtime libraries should be installed in a compiler-specific directory ],
@@ -26,7 +28,6 @@ AC_SUBST(target_alias)
GCC_LIBSTDCXX_RAW_CXX_FLAGS
AM_INIT_AUTOMAKE(foreign no-dist)
-AM_ENABLE_MULTILIB(, ..)
AM_MAINTAINER_MODE
# Calculate toolexeclibdir
--- a/src/libcilkrts/configure.ac
+++ b/src/libcilkrts/configure.ac
@@ -43,6 +43,8 @@
AM_MAINTAINER_MODE
+AM_ENABLE_MULTILIB(, ..)
+
# Build a DLL on Windows
# AC_LIBTOOL_WIN32_DLL
AC_PROG_CC
@@ -50,7 +52,6 @@
# AC_PROG_LIBTOOL
# AC_CONFIG_MACRO_DIR([..])
AC_CONFIG_FILES([Makefile libcilkrts.spec])
-AM_ENABLE_MULTILIB(, ..)
AC_FUNC_ALLOCA
# Check whether the target supports protected visibility.
Index: libquadmath/configure.ac
===================================================================
--- a/src/libquadmath/configure.ac
+++ b/src/libquadmath/configure.ac
@@ -23,6 +23,8 @@
AC_CANONICAL_SYSTEM
ACX_NONCANONICAL_TARGET
+AM_ENABLE_MULTILIB(, ..)
+
target_alias=${target_alias-$host_alias}
AC_SUBST(target_alias)
@@ -60,7 +62,6 @@
AC_SUBST(enable_static)
AM_MAINTAINER_MODE
-AM_ENABLE_MULTILIB(, ..)
AC_LANG_C
# The same as in boehm-gc and libstdc++. Have to borrow it from there.
